Burglar-alarm.



No. s5|,49|. Patehte d June 12, I900. F. Mc-MANUS.

BURGLAB ALARM.

(Application filed. Mar. 18, 1899.) (No Model.)

ZNITED STATES PATEN FFICE.

FRANK MOMANUS, OF OLEAN, NEW YORK.

BURGLAR-ALARM.

SPECIFICATION formingpart of Letters Patent No. 651,491, dated June 12, 1900,

Application filed March 18, 1899.

T0 ctZZ whom it may concern:

Be it known that I, FRANK MOMANUS, a citizen of the United States, residing at Olean, in the county of Oattaraugus, in the State of New York, have invented a certain new and useful Improvement in Burglar-Alarms, of which the following is a specification.

This invention relates to that class of burglar-alarms designed to give warning of the opening of a door.

The primary object of the invention is to secure great simplicity and effectiveness.

lVith this object in view the invention consists in the improved features and details of construction hereinafter set forth and claimed.

The accompanying drawings form a part of this specification and represent what I consider the best means of carrying out the in vention.

Figure 1 represents, on a small scale, the entire mechanism on the inner face of a door, the alarm being produced by a springhaninier striking a gong or hell. The remaining figures show details on a larger scale.

Fig. 2 shows the bell and hammer and the portion of the operating means immediately adjacent to the latter. The full lines show the parts in the position when the bell is in the act of striking or has just struck before the operating means has again returned to position ready for further operation. Fig. 3 is a face view of the knob and the adjacent portion of the connecting-wire in the idle position. Fig. t is a side view. Figs. 5 and 6 show the act of depressing and liberating the spring-hammer. Fig. 5 shows the relation in the first portion of the descending movement, and Fig. 6 shows the conditions at a later stage when the hammer-shank has twisted under the increasing strain and is in the act of being disengaged from the operating means to effect the blow. Figs. 7 and 8 show two views of the operating-lever,which is attached to the neck of the ordinary knob and operates the connecting-wire.

Similar letters of reference indicate corresponding parts in all the figures where they appear.

A is the door; A, a gong-bell of sufficient power fixed by a central screw at a high point on the inner face of the door; A a fixed stop,

Serial No. 709,620. (No model.)

and A A are guides which allow the motion of the operating wire or rod D, which acts onv the shank B of the spring-ham mer. This hammer-shank is an elastic wire formed into a helical spring B at the pivot-point A and carrying a head B at the opposite end arranged to strike the bell when it is liberated by the operating means.

E is the knob, which may be of any ordinary pattern, secured on a shank E by means of a screw E Connected mechanism allows the ordinary catch 0 to be drawn back by turning the knob a quarter-revolution to the right.

G is a crank-arm rigidly secured on the neck of the knob E by the same screw E which holds the knob. On the outer end of the arm G is a crank-pin G, which is grooved around. It receives a ring D, formed on the lower end of the operatingrod, holding it loosely in its groove, so that as the knob is turned a quarter-revolutioniin one direction it will pull down on the operating-rod D,and as it is turned or allowed to turn in the opposite direction it will cause the rod to rise. The ring D, which maybe formed by simply bending the wire of the rod, is adapted to engage with, be retained by, and be disengaged from the crank-pin G. The rod D is led through the lower guide A which may be simply a fiat staple or keeper, with liberty to move laterally as the crank-pin describes an arc, and at a higher point is led through a circular hole in the upper guide.

H is a spiral spring which incloses the rod D above the upper guide, abutting on this guide A and lifting with gentle force on a collar D At a sufficiently-higher point is a spear-head D When the parts are at rest, the spring-hammer shank B lies against the under side of the stop A with the hammer-head B out of contact with the adjacent surface of the gong A, and the spear-head D lies above the shank B, so that a little depression of the latter will engage it with the wing or side piece D and con1- mence to depress the hammer against the force of the helical spring H. The turning of the knob to effect the withdrawal of the ordinary catch will give this motion to the operating-rod D, and consequently to the spearhead D drawing the hammer downward.

During the first part of this movement the side wing D which may be simply a shelf or wide arm soldered or otherwise set rigidly on the front side of the hammer-shank B, remains level, simply sinking to an extent only a little in excess of the sinking of the shank to which it is attached; but as the strain increases it twists the shank of the hammer, and when it has reached a certain degree of tension the inclination has become such that it slips on tfrom its engagement with the spearhead, and the elasticity of the spring B throws theham mer forciblyupward and the hammerhead strikes the bell, giving a loud alarm. Then after the completion of the movement and the opening of the door the knob is allowed to return to its original position, the operating-rod D rises, carrying the spear-head up into contact with the side piece or Wing 13, which, owing to its grad ually-tapering form, is able to deflect itself and the ham mer-shank suliiciently to pass above the latter and resnine its normal position ready for a repetition of the operation.

Then at any time it is desired to throw the alarm out of action, so that the knob may be turned and the door operated in the usual way without giving the alarm, it is necessary simply to draw down the operating-rod slightly against the force of the spring II sufiiciently to release the ring from the groove in the crank-pin and to press the ring forward until it slips off the end of the crank-pin G. The operating-rod will then rise in obedience to the gentle force of the spring II until the collar D strikes the under side of the guide A This leaves the knob free to be turned in the ordinary way, the arm G turning with it, but without any effect, and no alarm will be given. \Vhen it is desired to again connect the alarm, the operating-rod D is again pulled down a little and the ring D again hooked on the crank-pin G.

Modifications maybe made Without departing from the principle or sacrificing the advantages ofthe invention.

I claim as my invention- The combination with a door A, of an ordinary gong mounted on the upper portion, a single horizontal length of wire external to said gong at one side thereof and contiguously carrying a hammer while the other end is coiled to afford the desired spring and provide an eye for a fastening-screw ei'iteringthe door, said length of wire having a lateral wing B and a second single length of wire or rod D, "ertically inclined, playing in suitable guides and carrying a barbed bead at its upper end and curved and directly connected at its lower end to an arm extending from the knob-spindle, substantially as herein specified.

In testimony that I claim the invention above set forth I affix my signature in presonce of two witnesses.

FRANK. MCMANUS.

w it n esses:

J. H. THOMPSON, W. L. PEL'roN. 

